1. Field of the Invention
The present invention relates to a device for pushing a winding of a knot through a space which is too small for conventional methods. More specifically, the present invention relates to a ligator for pushing a winding of a suture knot through an endoscopic portal.
2. Description of the Related Art
Several tools have been developed for tying knots at the distal end of an arthroscopic cannula. One such device consists of a ring at the end of a manipulatable rod. A suture winding is pushed by a distal end of the ring while one suture end passes through the ring. This type of knot pusher is unsatisfactory because it has no means for controlling the position of the winding. The winding may slip off the ring if tension is not accurately applied to the suture ends. Moreover, the winding tends to become locked into the ring. Moreover, the device and the winding do not form a streamlined system, resulting in frictional problems during use. For all of these reasons, the device is difficult to operate.
U.S. Pat. No. 4,602,635 to Mulhollan discloses a method of using a ligator to tie a knot through torn tissue. U.S. Pat. No. 2,610,631 to Calicchio discloses a ligator for tying a ligature loop around a blood vessel.
Other art of interest includes U.S. Pat. No. 4,641,652 to Hutterer, U.S. Pat. No. 3,752,516 to Mumma and U.S. Pat. No. 1,635,066 to Wells.